Compartimentum antebrachii posterius

Compartimentum antebrachii posterius

The compartimentum antebrachii posterius is a region located in the posterior aspect of the forearm. It is an anatomical compartment that contains various muscles, nerves, and blood vessels. In this article, we will explore the structures found within this compartment and their functions.

Anatomy

The compartimentum antebrachii posterius is bounded by the deep fascia of the forearm, which separates it from the other compartments of the forearm. It extends from the elbow joint to the wrist joint and is divided into two layers: the superficial layer and the deep layer.

The superficial layer of the compartimentum antebrachii posterius contains the following muscles:

• Musculus brachioradialis: This muscle originates from the lateral supracondylar ridge of the humerus and inserts into the styloid process of the radius. It functions to flex the forearm at the elbow joint and pronate the forearm.

• Musculus extensor carpi radialis longus: This muscle originates from the lateral supracondylar ridge of the humerus and inserts into the base of the second metacarpal bone. It functions to extend and abduct the wrist joint.

• Musculus extensor carpi radialis brevis: This muscle originates from the lateral epicondyle of the humerus and inserts into the base of the third metacarpal bone. It functions to extend and abduct the wrist joint.

• Musculus extensor digitorum: This muscle originates from the lateral epicondyle of the humerus and inserts into the extensor expansions of the second to fifth digits. It functions to extend the fingers at the metacarpophalangeal and interphalangeal joints.

The deep layer of the compartimentum antebrachii posterius contains the following muscles:

• Musculus supinator: This muscle originates from the lateral epicondyle of the humerus and inserts into the proximal part of the radius. It functions to supinate the forearm.

• Musculus abductor pollicis longus: This muscle originates from the posterior surface of the ulna and inserts into the base of the first metacarpal bone. It functions to abduct the thumb at the carpometacarpal joint.

• Musculus extensor pollicis brevis: This muscle originates from the posterior surface of the ulna and inserts into the base of the proximal phalanx of the thumb. It functions to extend the thumb at the metacarpophalangeal joint.

Innervation

The muscles within the compartimentum antebrachii posterius are innervated by the posterior interosseous nerve, a branch of the radial nerve. This nerve arises from the posterior cord of the brachial plexus and travels through the radial tunnel to reach the posterior aspect of the forearm. It provides motor innervation to the muscles mentioned above, allowing them to perform their respective functions.

Blood Supply

The blood supply to the compartimentum antebrachii posterius is primarily provided by the posterior interosseous artery, a branch of the common interosseous artery. This artery runs along with the posterior interosseous nerve and supplies oxygenated blood to the muscles and other structures within the compartment.

Clinical Significance

Injuries or conditions affecting the compartimentum antebrachii posterius can result in various symptoms and functional impairments. For example, damage to the posterior interosseous nerve can lead to weakness or paralysis of the muscles it innervates, causing difficulties with forearm and hand movements. Additionally, vascular disorders affecting the blood supply to this compartment can result in ischemia or tissue damage.

See Also

• Forearm
• Muscles of the forearm
• Radial nerve
• Brachial plexus